It has long been recognized that the skin or integument of multicellular organisms provides an important barrier between internal tissues of such organisms and the planetary environments in which such organisms live. One of the most important properties of biological skin in contrast non-biological skin is that biological skin usually possesses self-sealability whereas non-biological usually does not.
Among the major components of mammalian skins are various types of biologically generated proteins. Biologically generated proteins are copolyamino acids which have been synthesized on cellular ribosomes with amino acid sequences that are directed by nucleic acids.
However, it was discovered previously that thermal proteins can be made simply by heating amino acids together in a flask for several hours (Fox et al., 1958). Such compounds and methods for their preparation are described in U.S. Pat. Nos. 3,052,655 and 3,076,790, by Fox et al.
Thermal copolyamino acids form a class of thermally engineered proteins (TEPs) because they possess amino acid sequences that have not been currently found in nature. They sometimes are referred to as proteinoids to reflect the fact that, although they resemble proteins structurally and functionally, they are produced abiotically in contrast to biologically generated proteins such as collagen, to use just one example. They are also referred to as thermal proteins for the same reason. Organisms do not make proteins by heating amino acids.
Proteinoids, or TEPS, are much easier to make than proteins which are engineered by genetic means or by standard organic synthetic means.
It was previously found that thermal copolyamino acids, upon being heated in aqueous solution and allowed to cool, spontaneously form microspheres approximately one micron in diameter (Fox, 1960). Such microspheres have been found to mimic many of the properties of biological cells.
The object of this invention was to make a self-sealing artificial skin from thermal copolyamino acids, or TEps, that could mimic some of the proerties of biological skins.